The Book of Inversion and Duplex was a powerful magical book stolen from the Temple of the Winds.

Sister Amelia, under the control of Emperor Jagang, used the Book of Inversion and Duplex to spark the beginning of a firestorm in the form of a plague that began consuming the Midlands. Wizard Nathan Rahl bargained for the book from Jagang so that Kahlan Amnell could call upon the three Chimes, Reechani, Sentrosi, and Vasi in order to save Richard from the plague. By using sorcerer's sand and the Book of Inversion and Duplex, and beseeching the Chimes, Kahlan unleashed these creatures.

In Phantom, Zedd stated that the book was used to invert a Spell Form to find flaws within.